The present invention relates to an ink cartridge for containing liquid ink that can be mounted to and removed from a bubble jet printer for supplying the ink to an ink jet print head.
The ink container used with an ink jet recording apparatus is required to be capable of properly supplying an amount of ink corresponding to the amount of ink ejected from a recording head during the recording operation and to be free of ink leakage through the ejection outlets of the recording head when the recording operation is not executed.
When the ink container is of an exchangeable type, it is required that the ink container can be easily mounted or demounted relative to the recording apparatus without ink leakage, and that the ink can be supplied to the recording head with certainty.
A first conventional example of an ink container usable with the ink jet recording apparatus is disclosed which Japanese Laid-Open Patent Application No. 87242/1988, in which the ink jet recording cartridge has an ink container containing foamed material and having a plurality of ink ejecting orifices. In this ink container, the ink is contained in the porous material such as foamed polyurethane material, and therefore, it is possible to produce negative pressure by the capillary force in the foamed material and to prevent ink leakage from the ink container.
Japanese Laid-Open Patent Application No. 522/1990 discloses an ink jet recording cartridge in which a first ink container and a second ink container are connected with a porous material, and a second ink container and an ink jet recording head are connected with a porous material. In this second conventional ink cartridge, the porous material is not contained in the ink container, but is disposed only in the ink passage, so that the use efficiency of the ink is improved. By the provision of the secondary ink containing portion, the ink flowing out of the first ink container due to air expansion in the first ink container due to a temperature increase (pressure decrease) is stored, so that the vacuum in the recording head during the recording operation is maintained substantially constant.
However, in the first conventional example, the foamed material is required to occupy substantially the entire space in the ink container layer, and therefore the ink capacity is limited. In addition, the amount of the non-usable remaining ink is relatively large, that is, the use efficiency of the ink is poor. These are some problems therewith. In addition, it is difficult to detect the remaining amount of the ink, and it is difficult to maintain a substantially constant vacuum during the ink consumption period. These are additional problems.
In the second conventional example, when the recording operation is not carried out, the vacuum producing material is disposed in the ink passage, and therefore the porous material contains a sufficient amount of the ink, while the production of negative pressure by the capillary force of the porous material is insufficient, with the result that ink is leaked through the orifices of the ink jet recording head by a small impact or the like. This is a problem. In the case of an exchangeable ink cartridge in which the ink jet recording head is formed integrally with the ink container, and the ink container is mounted on the ink recording head, the second conventional ink cartridge is not usable. This is another problem.
Japanese Laid-Open Patent Applications Nos. 67269/1981 and 98857/1984 disclose an ink container using an ink bladder urged by a spring. This is advantageous in that the internal negative pressure is stably produced at the ink supply portion, using the spring force. However, these systems involve problems in that a limited configuration of the spring is required to provide a desired internal negative pressure, and the process of fixing the ink container to the bladder is complicated; the manufacturing cost therefore is high. In addition, for a thin ink container, the ink retaining ratio is small.
Japanese Laid-Open Patent Application No. 214666/1990 discloses a separated chamber type of ink container in which the inside space of the ink container is separated into a plurality of ink chambers, which communicate with each other by a fine hole capable of providing vacuum pressure. In the separate chamber type, the internal negative pressure at the ink supply portion is produced by the capillary force of the fine opening communicating the ink chambers. In this system, the structure of the ink container is simpler than the spring bladder system, which is advantageous from the standpoint of the manufacturing cost, and the configuration of the ink container is not limited by the structure. However, the separated chamber type involves the problem that when the ink container position is changed, the fine opening becomes short of ink depending on the remaining amount of the ink with resulting instability in the internal vacuum pressure even to the extent that the ink is leaked, and therefore, the ink container is limited in handling thereof.
Accordingly, it is a principal object of the present invention to provide an ink container, and ink jet recording head using the same and an ink jet recording apparatus using the same, which is easy to handle.
It is another object of the present invention to provide an ink container, an ink jet recording head using the same and an ink jet recording apparatus using the same in which the ink retaining ratio is high.
It is a further object of the present invention to provide an ink container, an ink jet recording head using the same and an ink jet recording apparatus using the same in which the ink is not leaked even if the ambient condition changes.
It is a further object of the present invention to provide an ink container, an ink jet recording head using the same and an ink jet recording apparatus using the same in which the vacuum in the ink supply is stabilized against ambient condition change, so that the ink can therefore be supplied to the recording head without influence to the ejection property of the ink.
It is a yet further object of the present invention to provide an ink container, ink, recording head, and ink jet recording apparatus in which the ink is efficiently used by the use of vacuum producing means.
It is a further object of the present invention to provide an ink container, ink, and ink jet recording head and an ink jet recording apparatus in which ink leakage is reliably prevented even when mechanical impact such as vibration or thermal impact such as temperature change is imparted to the recording head or the ink container under the condition of use or transportation of the ink jet recording apparatus.
According to an aspect of the present invention, there is provided an ink containing apparatus for containing ink, comprising: a negative pressure producing material; a container for containing the negative pressure producing material, such container having an air vent and a supply port for supplying the ink out; another container for containing ink; a communication part for communication between bottom portions of the containers; and ambient air introducing means adjacent to the air vent for introducing air into the communication part.
These and other objects, features and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.